1//===- llvm/CodeGen/WinEHFuncInfo.h -----------------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// Data structures and associated state for Windows exception handling schemes.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_CODEGEN_WINEHFUNCINFO_H
14#define LLVM_CODEGEN_WINEHFUNCINFO_H
15
16#include "llvm/ADT/DenseMap.h"
17#include "llvm/ADT/PointerUnion.h"
18#include "llvm/ADT/SmallVector.h"
19#include <cstdint>
20#include <limits>
21#include <utility>
22
23namespace llvm {
24
25class AllocaInst;
26class BasicBlock;
27class FuncletPadInst;
28class Function;
29class GlobalVariable;
30class Instruction;
31class InvokeInst;
32class MachineBasicBlock;
33class MCSymbol;
34
35// The following structs respresent the .xdata tables for various
36// Windows-related EH personalities.
37
38using MBBOrBasicBlock = PointerUnion<const BasicBlock *, MachineBasicBlock *>;
39
40struct CxxUnwindMapEntry {
41 int ToState;
42 MBBOrBasicBlock Cleanup;
43};
44
45/// Similar to CxxUnwindMapEntry, but supports SEH filters.
46struct SEHUnwindMapEntry {
47 /// If unwinding continues through this handler, transition to the handler at
48 /// this state. This indexes into SEHUnwindMap.
49 int ToState = -1;
50
51 bool IsFinally = false;
52
53 /// Holds the filter expression function.
54 const Function *Filter = nullptr;
55
56 /// Holds the __except or __finally basic block.
57 MBBOrBasicBlock Handler;
58};
59
60struct WinEHHandlerType {
61 int Adjectives;
62 /// The CatchObj starts out life as an LLVM alloca and is eventually turned
63 /// frame index.
64 union {
65 const AllocaInst *Alloca;
66 int FrameIndex;
67 } CatchObj = {};
68 GlobalVariable *TypeDescriptor;
69 MBBOrBasicBlock Handler;
70};
71
72struct WinEHTryBlockMapEntry {
73 int TryLow = -1;
74 int TryHigh = -1;
75 int CatchHigh = -1;
76 SmallVector<WinEHHandlerType, 1> HandlerArray;
77};
78
79enum class ClrHandlerType { Catch, Finally, Fault, Filter };
80
81struct ClrEHUnwindMapEntry {
82 MBBOrBasicBlock Handler;
83 uint32_t TypeToken;
84 int HandlerParentState; ///< Outer handler enclosing this entry's handler
85 int TryParentState; ///< Outer try region enclosing this entry's try region,
86 ///< treating later catches on same try as "outer"
87 ClrHandlerType HandlerType;
88};
89
90struct WinEHFuncInfo {
91 DenseMap<const Instruction *, int> EHPadStateMap;
92 DenseMap<const FuncletPadInst *, int> FuncletBaseStateMap;
93 DenseMap<const InvokeInst *, int> InvokeStateMap;
94 DenseMap<MCSymbol *, std::pair<int, MCSymbol *>> LabelToStateMap;
95 SmallVector<CxxUnwindMapEntry, 4> CxxUnwindMap;
96 SmallVector<WinEHTryBlockMapEntry, 4> TryBlockMap;
97 SmallVector<SEHUnwindMapEntry, 4> SEHUnwindMap;
98 SmallVector<ClrEHUnwindMapEntry, 4> ClrEHUnwindMap;
99 int UnwindHelpFrameIdx = std::numeric_limits<int>::max();
100 int PSPSymFrameIdx = std::numeric_limits<int>::max();
101
102 int getLastStateNumber() const { return CxxUnwindMap.size() - 1; }
103
104 void addIPToStateRange(const InvokeInst *II, MCSymbol *InvokeBegin,
105 MCSymbol *InvokeEnd);
106
107 int EHRegNodeFrameIndex = std::numeric_limits<int>::max();
108 int EHRegNodeEndOffset = std::numeric_limits<int>::max();
109 int EHGuardFrameIndex = std::numeric_limits<int>::max();
110 int SEHSetFrameOffset = std::numeric_limits<int>::max();
111
112 WinEHFuncInfo();
113};
114
115/// Analyze the IR in ParentFn and it's handlers to build WinEHFuncInfo, which
116/// describes the state numbers and tables used by __CxxFrameHandler3. This
117/// analysis assumes that WinEHPrepare has already been run.
118void calculateWinCXXEHStateNumbers(const Function *ParentFn,
119 WinEHFuncInfo &FuncInfo);
120
121void calculateSEHStateNumbers(const Function *ParentFn,
122 WinEHFuncInfo &FuncInfo);
123
124void calculateClrEHStateNumbers(const Function *Fn, WinEHFuncInfo &FuncInfo);
125
126} // end namespace llvm
127
128#endif // LLVM_CODEGEN_WINEHFUNCINFO_H
129